SpudFiles

i need a vavle to release pressure from a chamber into a barrel quickly and effeciently, what sould i do , what valve should i use or should i make or buy.

Try a moded sprinkler valve if u want a small bore launcher,but if u want to release more air and have more flow try ur hand at a piston valve gun.just look around on this site you will find out how to make them both.

How many cannons have you made? Because if this is your first, I would suggest the modded sprinkler valve and waiting a bit before you make a piston cannon.

Shrimphead, why?

The only skills you'll learn from your excursion with the modded sprinkler that'll be relevent to the construction of a diaphram/piston valve will be solvent welding and tapping... neither of which are terribly difficult.

And it's not really that hard to make one's own diaphram valve (can't speak for piston valves)... My very first cannon used one.

build whatever you are comfortable with

thanks for the help.
iv made some cannons befor but they where scrapped for spare parts,my new design is a little different.

Try a 3/4 inch QEV from http://www.valvestore.com.

You can get them a lot cheaper off of ebay. I suggest that you look there first for one of those.

if i buy stuff from ebay it will cost a shite load of money to ship it to south africa